This invention relates to limited rotation motors or galvanometers, with particular relevance to motors useful for direct writing recording in which the motor drives a stylus.
There is a need for such recorders, for instance for biological function measurement. The field has developed to the stage that three basic galvanometer-stylus systems are considered by the designer in seeking to find the best balance between the factors of performance, reliability, weight and cost. These are (A) open loop galvanometers with back EMF damping, (B) galvanometers with active velocity feedback, and (C) galvanometers with position and velocity feedback.
With electronic circuitry being compact, inexpensive, and reliable, lightweight battery-operated systems using such circuitry are particularly desired.